With Data Bridge, the access points for the WebAssist tools are under the WebAssist menu, not the Insert menu
1) you should create the form before adding UE
1a) No, Universal Email does not have a tool to create forms, either use Dreamweaver to create the form, or you can use CSS Form Builder
2) If you use the option in universal email to use one of the tempaltes to manage the email body, the templates include date and time information, you wont need a hidden form element.
hoever, you form element as configured uses:
<?php echo time(); ?>
this write a time stamp which is the number of seconds that have passed since 1/1/1970, for example:
1405610596
to write the current date, you would use the date function instead:
<?php echo(date("Y-m-d")); ?>